Thermal energy receiver

ABSTRACT

A thermal energy receiver having an infrared detector array mounted in a detector-vacuum module and a refrigerator for cooling the detector to an operating temperature is disclosed. The detector-vacuum module includes a dewar having a cold finger supporting a detector array mount and an infrared detector array attached to the mount. The refrigerator includes a cold finger having at one end a heat transfer mechanism, a regeneratordisplacer having an annulus structure, and an off-axis drive mechanism interconnecting the regenerator-displacer and a compressor piston to a driver motor. The heat transfer mechanism provides greater efficiency in cooling the detector array, the annulus provides a cryogen passage from the compressor to the regenerator-displacer throughout reciprocation thereof to eliminate &#39;&#39;&#39;&#39;dead-space&#39;&#39;&#39;&#39; when the displacer is mounted in a closed cylinder, and the off-axis drive mechanism structure provides a large bearing structure which resists axial movement due to shock vibration.

United States Taylor et al.

[ Nov. 26, 1974 THERMAL ENERGY RECEIVER Inventors: Carol 0. Taylor,Anna; Stephen L.

Whicker, Dallas, both of Tex.

Assignees Texas instruments incorporated,

Dallas, Tex.

Filed: June 25, 1973 Appl. N0.: 373,352

References Cited UNITED STATES PATENTS 9/1960 Fong 250/352 7/1966Lederhandler... 250/352 2/1968 Toussaint 250/551 6/l973 Hoffman 250/347Primary Examiner-Harold A. Dixon Attorney, Agent, or Firm-Harold Levine;Rene E. Grossman; Alva H. Bandy [57] ABSTRACT A thermal energy receiverhaving an infrared detector array mounted in a detector-vacuum moduleand a refrigerator for cooling the detector to an operating temperatureis disclosed. The detector-vacuum module includes a dewar having a coldfinger supporting a detector array mount and an infrared detector arrayattached to the mount. The refrigerator includes a cold finger having atone end a heat transfer mechanism, a regenerator-displacer having anannulus structure, and an off-axis drive mechanism interconnecting theregenerator-displacer and a compressor piston to a driver motor. Theheat transfer mechanism provides greater efficiency in cooling thedetector array, the annulus provides a cryogen passage from thecompressor to the regenerator-displacer throughout reciprocation thereofto eliminate dead-space" when the displacer is mounted in a closedcylinder, and the off-axis drive mechanism structure provides a largebearing structure which resists axial movement due to shock vibration.

16 Claims, 8 Drawing Figures DETECTOR To 124/ a userno OPTtCS,/4

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PATENIE 1291/26 1974 3851.173 sum 2 or 5 PATENTEL W 3,851 1 73 sum 30F sDISPLACER TOP DEAD CENTER A DEAD CENTER- DISPLACER BOTTOM DEAD CENTERCOMPRESSOR BOTTOM V DEAD CENTER This invention relates to a thermalenergy detector and more particularly to an infrared receiver.

In the past infrared receivers have had the detector array permanentlymounted upon the cold finger of the refrigerator, and the refrigeratorhas been either an open cycle or closed cycle refrigerator system.

Many problems have resulted from use of the abovementioned structures ininfrared receivers. These problems stem from the reliability,maintainability, power, heat dissipation, and weight of such prior artsystems. For example, the reliability of the prior art systems have beendependent upon the mean time before failare of the refrigerators ratherthan the detectors; thus, an improved refrigerator would increase thelife time of the receiver. For another example, the maintenance of thereceiver, with the detector permanently attached to the refrigerator,has required that the entire receiver be returned for repair. Thus, amodular construction would permit the interchange of parts and result insubstantial savings in the maintenance and repair of infrared receivers.

Accordingly, it is an object of this invention to provide an improved,highly reliable thermal energy receiver which is economical tomanufacture.

Another object of the invention is to provide a modular thermal energyreceiver, which is easy and economical to maintain and repair.

Still another object of the invention is to provide an efficientrefrigerator system for a detector-vacuum module of the thermal energyreceiver.

Yet another object of the invention is to provide a detector-vacuummodule for an infrared receiver which is readily detached from therefrigerator system for replacement purposes.

A further object of the invention is to provide a heat transfermechanism for increasing the thermal transfer efficiency between thedetector-vacuum module and the refrigerator of the thermal energyreceiver.

The above and other objects of this invention are accomplished byproviding a modular type thermal energy receiver which comprises fourseparate or independent modules; namely, a cryogenic cooler orrefrigerator, an optical scanner, a detector-vacuum module, and anelectro-optics module. The cryogenic. cooler may be, for example, eithera Joule-Thomson cooler or cryostat, or a closed cycle refrigerator suchas that disclosed in U.S. Pat. No. 3,334,491 issued Aug. 8, 1967. Therefrigerator disclosed in the patent has been moditied to incorporatenovel features such as a modified off-axis drive mechanism and cryogenline arrangement between the compressor and cold chamber to improve thecooling efficiency and reliability of the refrigerator. A novel heattransfer mechanism is provided between the refrigerator cold finger andthe cold finger of the detector vacuum module for the efficient coolingof the detector array mounted in the detector-vacuum module. Theremovable detector-vacuum module includes a cooling member mating witheither the cryostat or the cold finger of the refrigerator. The coolingmember of the detector vacuum-module forms the interior wall of a dewarvacuum chamber and has electrical leads etched thereon to connect thedetectors of the detector array to the multiple pin outlets for theelectro-optics module connectors. The electro-optics module may be. forexample, that disclosed in US. Pat. No. 3,742,238

issued June 26, 1973, and assigned to common assignee Texas InstrumentsIncorporated.

Other objects and features of this invention will become more readilyapparent from the following detailed description when read inconjunction with the accompanying drawings in which:

FIG. 1 is a block diagram of the thermal energy receiver constitutingthe subject matter of this invention;

FIG. 2 is an isometric view of the infrared receiver embodiment of theinvention;

FIG. 3 is a view, partly in section, disclosing the offaxis drivemechanism and cryogenic flow system of the refrigerator;

FIG. 4 is a view, partly in section, disclosing the motor drivemechanism for the off-axis drive mechanism of the refrigerator;

FIG. 5 is a plot of the operating cycle of the refrigerator;

FIG. 6 is a partial view of the infrared receiver showing the detailsand relationship of the heat transfer mechanism to the refrigerator coldfinger and the cold finger of the detector-vacuum module;

FIG. 7 is a view partly in section showing the relationship of the partsof the detector-vacuum module to the cold finger of the refrigerator;and

FIG. 8 is an exploded view of the cryostat and adapter embodiment of theinvention.

Referring now to the drawings, the thermal radiation receiver 10 isshown in FIG. 1 as a. block diagram to illustrate the operationalrelationship of the major components. The thermal radiation receiver 10(FIGS. 1 and 2) comprises an optical scanner 11, detector array 12,electro-optics l4, vacuum module 16, and refrigerator 18. The detectorarray 12 is in the path of incoming thermal energy scanned by opticalscanner 11 to which it is responsive to produce electrical signalsrepresentative of the thermal energy image impinging thereon. Theelectrical signals of the detector array 12 are processed for display ina selected one of many electro-optical systems 14. An example of asuitable electro-optics display system is the system of previouslyreferred to US. Pat. No. 3,742,238 issued June 26, 1973. The detectorarray 12 is mounted for cooling in a detector-vacuum module 16. Thedetector or detector array 12 of the detector-vacuum module 16 is cooledby a suitable cooler such as, for example, a refrigerator 18 or cryostat18 (FIG. 8). The refrigerator 18 (FIGS. 1 and 2) must have a sufficientcooling capacity to cool the detector array to its operatingtemperature. The system hereinafter described is particularly suitablefor cooling an infrared detector array such as, for example, a mercury,cadmium telluride detector array to a temperature of about 77K or below.

In the preferred embodiment of the invention the thermal energy detector10 is cooled by a closed cycle refrigerator such as a Stirling CycleCooler 20 (FIG. 3). The refrigerator system is comprised of two majorcomponents; namely, a compressor 22 and a cooling head 24. The majorcomponents are interconnected by a common drive mechanism 26 driven by amotor 28. Except for the cooling head which is attached to housing 30,all of the components are mounted in the housing 30. The working fluidor cryogen, which may be for example, helium, flows freely between thecompressor and cooling head as will be hereinafter described; that is,no valves are included in the cyrogen system for controlling the flow ofthe cryogen. The compressor 22 is preferably an air cooled, drylubricated unit of single piston design. The cooling head 24 (FIG. 3)consists of a regenerator-displacer 32, and an annulus 34 which, asshown, is formed as an integral part of the regenerator-displacer 32.

The motor 28 (FIG. 4) may be, for example, an electrical motor of aboutone-twentieth horsepower powered by either a dc or a.c. source of powerto rotate a drive shaft 36 mounted in ball bearings 38. Drive shaft 36is connected to a geared speed reducer consisting of spur gears 40 and42. Spur gear 40 is a driving pinion gear 40 and the other spur gear 42is a driven gear. The driven gear 42 is mounted on output shaft 44journaled in ball bearings 46. The output shaft 14, which is driven atabout 1,500 rpm, has an eccentric cam 48 (FIG. 3) mounted thereonengaging bearing surface 50 of master piston connecting rod 52. Themaster piston rod 52 (FIG. 3) is connected to compressor-piston 54 bypin 56 passing through the pistons skirt. The compressor piston 54,which has a diameter of about 1 inch, is mounted in compression cylinder58, formed in housing 30. A boss 60 is formed on the eye, which has adiameter of about 1 inch, of the master rod 52 at right angles to therod portion thereof. An auxiliary or slave rod 62 has one end pivotallyconnected to the boss 60 by pin 64 and at its other end pivotallyconnected to ears 66 of the regenerator-displacer 32, which has adiameter of about /2 inch, mounted in a cylinder or cold finger 70. Thisoff-axis drive mechanism, when driving the piston andregeneratordisplacer of the above-mentioned sizes, produces no forcecouple about the crank axis, and the master rod provides a wide bearingseat on the crank that resists rod rotation while maintaining lowbearing loads. It has been found that this arrangement increasessubstantially the reliability of the refrigerator.

The regenerator-displacer 32 includes a displacer cylinder 72 enclosinga heat exchanger 74 such as, for example, a plurality (about 850) offine (about 325-400) mesh metal (stainless steel) screens. The displacercylinder 72 is about V2 inch in diameter and is made of plastic such as,for example, Lexan or fiberglass. An annulus 34 is formed in theperiphery of the cylinder 72 adjacent the ear bearing end. As theannulus 34 is formed as part of the reciprocating regenerator-displacer,it is referred to as a floating annulus. A plurality of ports 78 areprovided in the bottom of the annulus 34 which provide passages to theheat exchanger 74. The cylinder 72 has a plurality of ports 80 in theend opposite the annulus 34; these ports provide passages into a coldchamber 82 defined by the space between the cylinder 72 and the interiorof cold finger 70. The annulus 34 of the cylinder 72 is sealed off fromthe cold chamber 82 and the off-axis drive mechanism chamber by a pairof seals 84 and 86 such as those sold under the trademark Bal Seals (aspring loaded Teflon) which are in sealing engagement with the interiorof the cold finger 70 above and below the annulus 34. These seals 84 and86 also provide axial motion guides for the regenerator-displacer. Thefloating annulus substantially eliminates the dead space of systemsutilizing a stationary cylinder with a reciprocating heat exchangermounted therein. The only dead space being that of the annulus 34. Theminimum annulus volume is determined by the allowable pressure droptherein.

The cold finger has a lower portion defined by an outwardly extendingflange 88 and an open end 89. The open end 89 is seated in a boreprovided therefore in the housing 30. A sealing ring 90 seals the spacebe tween the cold finger 70 and the housing 30 to prevent the escape ofcryogen from that part of the housing 30 enclosing the off-axis drivemechanism 26. A retaining member 94 has a lower flange 96 attached tohousing 30 and an upper flange 98 which has an annular recess 100 inwhich the flange 88 of the cold finger is seated.

The cold finger 70 has a manifold 102 having a plurality of ports 104 incommunication with the annulus 34 of the regenerator-displacer 32. Themanifold 102 is also in communication with an air cooled passage 106 ofhousing 30 opening into the compression cylinder 58.

The volumes of the compression cylinder 58, housing passage 106, coldfinger manifold 102, regeneratordisplacer annulus 34, cylinder 72, andcold chamber 82 form the cryogen line which is filled with a suitablecryogen such as, for example, helium.

In operation, the regenerator-displacer 32 and the compression piston 54being connected to the off-axis drive mechanism 26, operate alongintersecting axes and 90 out of phase with one another. Thus, as theregenerator-displacer 32 reciprocates, the volume of the cold chamber 82decreases and increases in accordance with the following description ofone operating cooling cycle.

The refrigeration cycle may best be understood be referring to FIG. 5wherein the letters A, B, C, and D represent the positions of theregenerator-displacer 32 and the compression piston 54 as follows:positions A and B represent respectively the top dead center positionsof the regenerator-displacer and the compressor piston, and positions Cand D represent respectively the bottom dead center positions of theregeneratordisplacer 32 and the compressor piston. It is known that inthe Stirling Cycle the cryogen flowing through the regenerator-displacerabsorbs heat from the regenerator mass during its flow from the colderend of the regenerator to the hotter end and gives up heat to theregenerator mass during its flow from the hotter end to the cooler end.It is also known that the cryogen is cooled and densified in passingthrough the regenerator-displacer and during its expansion in the coldchamber. Thus, at position A the regenerator-displacer 32 has reachedtop dead center and the compressor piston 54 has reached the mid-pointof its compression stroke in cylinder 58. At this point the cryogenpressure is approaching its maximum value and the volume of the coldchamber is increasing from a minimum. The regenerator mass is absorbingheat from the cryogen. At position B the regenerator-displacer 32 hasbeen withdrawn through the cryogen flowing into the cold chamber and thevolume of the cold chamber has increased to one-half its maximum; thecompressor piston 54 has arrived at top dead center to complete itsupward stroke. The cryogen has passed its maximum pressure point and thepressure has returned to an intermediate value. At point C theregenerator-displacer 32 is at bottom dead center and the compressionpiston 54 has proceeded downwardly to the midpoint of compressioncylinder 58. The cryogen pressure has further decreased and the coldchamber is at its maximum volume. The cryogen at this point isapproaching the completion of its expansion and its flow is back throughthe regenerator mass collecting heat on its way to the compressioncylinder 58. At point D, the regeneratordisplacer has moved upwardly toreduce in half the volume of the cold chamber 82 and the compressorpiston has reached bottom dead center. At this point the cryogen haspassed its lowest pressure point and the pressure is on the rise; thevolume of the cold chamber has passed its maximum volume and its volumehas reduced to about one-half its maximum volume. The cryogen is nowbeing compressed and is flowing out of the compression cylinder 58. Thecycle is completed when the regenerator-displacer returns to itsposition at point A. It will be understood that the heat of compressionof the cryogen is dissipated through the housing 31) and the cryogenenters the regenerator at the ambient temperature on its way to the coldchamber 82 where it reaches its cooling temperature, and upon its returnthrough the regenerator mass it collects heat and leaves the regeneratorat the ambient temperature and reenters the compression cylinder foranother cycle.

The cold finger 70, as previously mentioned, is cooled by the extractionof heat therefrom by the re frigerator and in the past, the detectorarray was mounted directly on the exterior wall of the cold finger 70and the dewar was formed therewith. However, to improve maintenancecapability a detector-vacuum module 16 (FIG. 7) which is removable fromthe cold finger 70 is used in the embodiment of the present invention.To alleviate the loss of cooling capacity the cold finger 7th isprovided with a heat transfer mechanism 110 (FIG. 6). The heat transfermechanism includes a coupling member 112 having an H crosssection. Thelower portion of the coupling member 112 is configured after theconfiguration of the cold finger 70 upon which it is mounted and securedby brazing, for example. The upper portion of the coupling member isopened and seats a coil spring 114 together with a depending portion offlanged member 116. The spring 114 biases the flanged member 116 intoengagement with the detector-vacuum module 16. The heat transfermechanism may be coated with a material having a high heat transfercoefficient such as a silver filled silicon grease, or the flangedmember 116 may include a flexible heat transfer strip 118 of a heatconducting metal as shown in dotted lines in FIG. 6. The heat conductingmetal flex strip 118 has one end portion attached to the flanged member116 and the other end attached to the cross member of the couplingmember 112, or if the cross-memberis cut out as shown in FIG. 6, to theend of the cold finger 71). Another arrangement for the heat transfermechanism eliminates the coupling member 112 by making the flangedmember 116 a coupling member which fits slidingly over the cold fingerwith the spring 114 therebetween.

The detector-vacuum module 16 (FIG. 7) includes a cylinder or secondcold-finger 120. The cylinder 120 has walls 122 formed of a suitableinsulating material such as a hard glass sold as Corning Glass No. 7052,an open end and a closed end 124 of a suitable metal or glass. The metalend 124 is constructed of a metal alloy having a glass matchingcoefficient of expansion such as the metal alloy sold under thetrademark Kovar. The combination of Coming Glass No. 7052 and Kovar ispreferred as the temperature coefficients of expansion are compatible.The open end of the cylinder is formed by a metal ring 126 alsoconstructed, for example, of the Kovar metal alloy. The metal ring 126is attached to an adapter 128 having a lower flange 130 and an uppersupport flange 132. The lower flange 130 receives O-ring 134 andfasteners such as screwed or bolts 136 for attachment to the upperflange 98 of the cold finger retaining member 94.

The detector array 12 is attached by a suitable bonding material such asan epoxy to a mount 138 attached to the metal or glass end 124 ofcylinder 120. A plurality of leads 141) (220 for a 180 element detectorarray) are provided which connect the detectors of the detector array 12to a plurality of lead terminals 142 of leads 144. The lead terminals142 are formed on insulating material attached to the metal end 124, andthe leads are attached by any suitable technique such as ball bonding.The leads 144 are preferably metalized on the glass walls 122 ofcylinder 120, and are connected to ends of a lead pattern 146 formed ona flat annular disk 148. The disk 148 is formed from an insulatingmaterial which, for example, may be of a ceramic material. The annularring 148 circumscribes the cylinder 120 and is supported by the uppersupport flange 132. The lead pattern 146 may be formed by metalizing alead pattern on the ceramic ring 148.

The lead pattern 146 includes at ends opposite those connected to leads144 a plurality of terminals connected to conductor posts 150 mounted inholes in the ceramic ring 148. The posts 150 extend above and below theceramic ring 148. A plurality of resistor biasing packs 152 are attachedbeneath the ceramic ring 148. For example, four biasing packs 152 areprovided each carrying 45 resistors 154 connected to the lower ends ofconductor posts 150. The lower ends of posts 150 are also attached to acorresponding number of leads which may be formed on an H film 156having their other ends attached to receptacle 157 for the electricalinput terminals of the detector-vacuum module 16. The receptacle 157 issupported by bracket and gusset 160. The electrical input terminals 158,which are connected to the output terminals 157 of the infraredreceiver, are attached to the electro-optics package 14, and supply abias for the detector circuits from a bias power source and receive thebiased output of the detector array 12.

The detector array 12 is enclosed by a cylinder 166 having an open endsecured to a flange of adapter 170. The other end of the adapter isattached to a support member 172 sealing the adapter to the ceramic ring148 to form a vacuum chamber 174 between the cylinders 120 and 166. Apinch tube 175 is used to provide the vacuum in vacuum chamber 174.

The vacuum chamber is equipped with a getter 176 mounted in cylinder166. The active getter 176 is connected to a source of power (not shown)and fired on an as required basis to maintain the vacuum in the vacuumchamber 174. The getter 176 which may be, for example, SAESnon-evaporable active getter material, extends substantially the life ofthe detector-vacuum module 16. A shield 178 surrounds a substantialportion of the walls of cylinder 120 to protect the cold finger andcylinder 122 from the action of the getter 176 and to reduce dewarthermal heat leak; it is mounted in the support member 172.

A housing 181) encloses the components of the detector-vacuum module 16.The housing 180 has an in wardly extending flange 182 to which aretaining member 1183 is attached by screws 184 to support flange 130for rotation. The rotation of flange 130 permits positional adjustmentof the detector array to the optical scanner 11 to effect properscanning action for the field of view.

The biased outputs of the detectors of the detector array 12 are fed tothe electro-optical system l4. Although the electro-optical system 14 isdetermined by the type of display desired, many systems are known tothose skilled in the art. A suitable electro-optical system is shown inthe above-mentioned US. Pat. No. 3,742,238 issued June 26, 1973.

In another embodiment of the invention the refrigerator is replaced by asuitable cryostat such as, for example, Joule-Thomson cryostat 18' shownin FIG. 8. To provide a versatile system; that is, one which can useeither a refrigerator or a cryostat with the detectorvacuum module, thedetector-vacuum module 16 is designed to receive the cold finger '70 ofthe refrigerator or an adapter member 186 (FIG. 8) for a cryostat. Theadapter 186 is made of a suitable material such as, for example, anexpanded synthetic resinous material sold under the trademark Styrofoam.To make a cryostat operative it is essential that the cryogen pass downthe cryostat walls in close approximation thereof. The adapter 186 fillsthe space between the cylinder 120 of the detector-vacuum module and thecryostat l8 necessary for the proper operation of the cryostat.

In operation of the infrared receiver 10, the refrigerator 18 isactivated to cool the detector array 12 to its operating temperature.The infrared receiver is then directed to a desired field of view;infrared energy emanating from the subject of the field of view impingesupon the detectors of the detector array 112. The detectors produceelectrical signals representative of the intensity of the infraredenergy. These electrical signals are biased by a standard bias toprovide signals of a strength suitable for processing by theelectro-optical system 14. Processing includes amplification of thesignals and applying them to light emitting diodes for producing visiblelight signals which may be televised, displayed upon a screen, or vieweddirectly as desired.

Although several embodiments of this invention have been describedherein, it will be apparent to a person skilled in the art that variousmodifications to the details of construction shown and described may bemade without departing from the scope of this invention.

What is claimed is:

l. An infrared receiver comprising:

a. an infrared detector in a scanning path of infrared energy emanatingfrom a source thereof for producing electrical signals representative ofimpinging infrared energy;

b. a detector-vacuum module including an elongated vacuum chamber oneend wall of which forms a first cold finger having integral therewith aseat portion rigidly supporting the infrared detector thereon, and anelectrical conductor means coupled to the detector for collecting theelectrical signals produced by the detector;

c. a refrigerator means having a motor driven compressor, a coolingmember including a second elongated cold finger, means for selectivelycoupling the second cold finger of the cooling member in sealingengagement within and in conductive contact with said end of the firstcold finger of the detector-vacuum module for cooling the detector to anoperative temperature for producing the electrical signals, saiddetector-vacuum module removably attached to said cooling member; and

d. an electro-optical system coupled to the electrical conductor meansof the detector-vacuum module for processing video signals from theelectrical signals produced by the infrared detector.

2. An infrared receiver according to claim I wherein said infrareddetector is a mercury cadmium telluride detector array.

3. An infrared receiver comprising:

a. an optical scanner for scanning a scene;

b. an infrared detector in the scanning path of infra red energyemanating from the scene scanned by the optical scanner for producingelectrical signals representative of impinging infrared energy;

0. a detector-vacuum module having a first tubular member having an openend with an outwardly extending flange, a detector seat to which theinfrared detector is attached, said detector seat closing the end of thefirst tubular member opposite to the open end; a second tubular membersurrounding the first tubular member to form a vacuum chambertherebetween and electrical conductors having terminals mounted on thedetector seat connecting the infrared detector and terminals exteriorlyof the second tubular member;

(1. a refrigerator means having a motor driven compressor, a coolingmember, and an outwardly extending flange corresponding to the outwardlyextending flange of the detector-vacuum module, the cooling member incontact with the detector seat of the detector-vacuum module for coolingthe detector to an operative temperature for producing electricalsignals representative of the scanned scene, said outwardly extendingflange member at the open end of the detector-vacuum module beingattached for rotation on the corresponding flange of the refrigeratorfor positionally adjusting the detector as to the optical scanner; and

e. an electro-optical system coupled to the electrical conductor meansof the detector-vacuum module for processing video signals from theelectrical signals produced by the infrared detector.

41. An infrared receiver according to claim 3 wherein the refrigeratorcooling member is a cryostat and the detector-vacuum module furtherincludes a guide member in sealing engagement with the first tubularmember of the detector-vacuum module, said guide member operative toretain the flow of gas from the cryostat adjacent the cryostat;

5. An infrared receiver according to claim 3 wherein portions of thedetectors electrical conductors are leads metalized on the first tubularmember.

6. An infrared receiver according to claim 5 wherein portions of thedetectors leads include an H film pattern of electrical leadsinterconnecting theplurality of electrical conductor posts of theinsulator disk to the output terminals of the detector-vacuum module.

7. An infrared receiver according to claim 3 wherein the refrigeratorcooling member includes a cold finger.

8. An infrared receiver according to claim 7 wherein the cold finger ofsaid refrigerator means includes a spring biased heat transfermechanism.

9. An infrared receiver according to claim 7 wherein the cold finger ofsaid refrigerator means comprises a tubular member correspondinglyshaped to fit within the vacuum chamber of the detector-vacuum module,said tubular member having an open end in communication with therefrigerator and a closed end with a recess forming a wall therein, aspring biased plate member mounted in said well, the spring of saidspring biased plate member operative to maintain the plate member inContact with the detector-vacuum'module seat for the infrared detector.

10. An infrared receiver according to claim 9 wherein said spring biasedplate member further includes an expandable heat conducting ribbon forconducting heat from the infrared detector seat to the cold finger.

11. An infrared receiver according to claim 10 wherein the spring biasedplate member further in cludes a base plate member attached to the endof the spring biased plate member opposite the plate and wherein saidexpandable heat conducting ribbon is positioned between the plates withend portions attached thereto.

12. An infrared receiver according to claim 3 further including anelectrical feedthrough comprising an insulator disk extending beyond thesecond tubular member and having an aperture through which the firsttubular member is positioned, said insulator disk including a pluralityof electrical conductor posts mounted in the insulator disk exteriorlyof the second tubular member and a lead pattern of electrical conductorsmetalized on the insulator disk, the leads connected tothe electricalconductor posts and extending inwardly toward the inner periphery of theinsulator disk, the insulator disk, lead pattern and posts forming afeedthrough through the second tubular member for the detector'selectrical conductors.

L3. An infrared receiver according to claim 12 furth er includingplurality of resistor biasing packs conne'cted to the insulator disk,the packs including a plurality of resistor circuits selectively coupledto the electrical conductor posts of the insulator disk for electricallybiasing the detector outputs.

14. An infrared receiver according to claim 13 wherein the detector is amercury cadmium telluridc detector and portions of the detectors leadinclude an H film pattern of electrical leads interconnecting theplurality of electrical conductor posts of the insulator disk to theoutput terminals of the detector-vacuum module and input of biasingpower.

15. An infrared receiver according to claim 3 further including a gettermeans in communication with the vacuum chamber and operativelyresponsive to electrical signals for maintaining a vacuum in said vacuumchamber.

16. An infrared receiver according to claim 15 further including aradiation shield for protecting the cooling member from radiation.

1. An infrared receiver comprising: a. an infrared detector in ascanning path of infrared energy emanating from a source thereof forproducing electrical signals representative of impinging infraredenergy; b. a detector-vacuum module including an elongated vacuumchamber one end wall of which forms a first cold finger having integraltherewith a seat portion rigidly supporting the infrared detectorthereon, and an electrical conductor means coupled to the detector forcollecting the electrical signals produced by the detector; c. arefrigerator means having a motor driven compressor, a cooling memberincluding a second elongated cold finger, means for selectively couplingthe second cold finger of the cooling member in sealing engagementwithin and in conductive contact with said end of the first cold fingerof the detector-vacuum module for cooling the detector to an operativetemperature for producing the electrical signals, said detector-vacuummodule removably attached to said cooling member; and d. anelectro-optical system coupled to the electrical conductor means of thedetector-vacuum module for processing video signals from the electricalsignals produced by the infrared detector.
 2. An infrared receiveraccording to claim 1 wherein said infrared detector is a mercury cadmiumtelluride detector array.
 3. An infrared receiver comprising: a. anoptical scanner for scanning a scene; b. an infrared detector in thescanning path of infrared energy emanating from the scene scanned by theoptical scanner for producing electrical signals representative ofimpinging infrared energy; c. a detector-vacuum module having a firsttubular member having an open end with an outwardly extending flange, adetector seat to which the infrared detector is attached, said detectorseat closing the end of the first tubular member opposite to the openend; a second tubular member surrounding the first tubular member toform a vacuum chamber therebetween and electrical conductors havingterminals mounted on the detector seat connecting the infrared detectorand terminals exteriorly of the second tubular member; d. a refrigeratormeans having a motor driven compressor, a cooling member, and anoutwardly extending flange corresponding to the outwardly extendingflange of the detector-vacuum module, the cooling member in contact withthe detector seat of the detector-vacuum module for cooling the detectorto an operative temperature for producing electrical signalsrepresentative of the scanned scene, said outwardly extending flangemember at the open end of the detector-vacuum module being attached forrotation on the corresponding flange of the refrigerator forpositionally adjusting the detector as to the optical scanner; and e. anelectro-optical system coupled to the electrical conductor means of thedetector-vacuum module for processing video signals from the electricalsignals produced by the infrared detector.
 4. An infrared receivEraccording to claim 3 wherein the refrigerator cooling member is acryostat and the detector-vacuum module further includes a guide memberin sealing engagement with the first tubular member of thedetector-vacuum module, said guide member operative to retain the flowof gas from the cryostat adjacent the cryostat.
 5. An infrared receiveraccording to claim 3 wherein portions of the detector''s electricalconductors are leads metalized on the first tubular member.
 6. Aninfrared receiver according to claim 5 wherein portions of thedetector''s leads include an ''''H'''' film pattern of electrical leadsinterconnecting the plurality of electrical conductor posts of theinsulator disk to the output terminals of the detector-vacuum module. 7.An infrared receiver according to claim 3 wherein the refrigeratorcooling member includes a cold finger.
 8. An infrared receiver accordingto claim 7 wherein the cold finger of said refrigerator means includes aspring biased heat transfer mechanism.
 9. An infrared receiver accordingto claim 7 wherein the cold finger of said refrigerator means comprisesa tubular member correspondingly shaped to fit within the vacuum chamberof the detector-vacuum module, said tubular member having an open end incommunication with the refrigerator and a closed end with a recessforming a wall therein, a spring biased plate member mounted in saidwell, the spring of said spring biased plate member operative tomaintain the plate member in contact with the detector-vacuum moduleseat for the infrared detector.
 10. An infrared receiver according toclaim 9 wherein said spring biased plate member further includes anexpandable heat conducting ribbon for conducting heat from the infrareddetector seat to the cold finger.
 11. An infrared receiver according toclaim 10 wherein the spring biased plate member further includes a baseplate member attached to the end of the spring biased plate memberopposite the plate and wherein said expandable heat conducting ribbon ispositioned between the plates with end portions attached thereto.
 12. Aninfrared receiver according to claim 3 further including an electricalfeedthrough comprising an insulator disk extending beyond the secondtubular member and having an aperture through which the first tubularmember is positioned, said insulator disk including a plurality ofelectrical conductor posts mounted in the insulator disk exteriorly ofthe second tubular member and a lead pattern of electrical conductorsmetalized on the insulator disk, the leads connected to the electricalconductor posts and extending inwardly toward the inner periphery of theinsulator disk, the insulator disk, lead pattern and posts forming afeedthrough through the second tubular member for the detector''selectrical conductors.
 13. An infrared receiver according to claim 12further including a plurality of resistor biasing packs connected to theinsulator disk, the packs including a plurality of resistor circuitsselectively coupled to the electrical conductor posts of the insulatordisk for electrically biasing the detector outputs.
 14. An infraredreceiver according to claim 13 wherein the detector is a mercury cadmiumtelluride detector and portions of the detector''s lead include an''''H'''' film pattern of electrical leads interconnecting the pluralityof electrical conductor posts of the insulator disk to the outputterminals of the detector-vacuum module and input of biasing power. 15.An infrared receiver according to claim 3 further including a gettermeans in communication with the vacuum chamber and operativelyresponsive to electrical signals for maintaining a vacuum in said vacuumchamber.
 16. An infrared receiver according to claim 15 furtherincluding a radiation shield for protecting the cooling member fromradiation.